OMAHA, Neb. (AP) -- Tyler Buffett limited Arizona to three hits over eight innings, and Oklahoma State took command of its bracket in the College World Series with a 1-0 victory Monday night.

The Cowboys, who beat UC Santa Barbara by the same score on Saturday, became the first team in the CWS' 70 years to win back-to-back 1-0 games.

Buffett (9-3) allowed three singles in the first five innings, walked two and struck out six. Trey Cobb took over in the ninth and earned his sixth save.

Oklahoma State scored in the fourth when Donnie Walton doubled and came home on Garrett Benge's single. Otherwise, Buffett and Arizona starter Bobby Dalbec (10-5) matched zeroes through eight innings the same way the Cowboys' Thomas Hatch did with UC Santa Barbara's Shane Bieber on Saturday.

Dalbec, drafted as a third baseman in the fourth round by the Boston Red Sox, held the Cowboys to five hits and struck out a career-high 12.

The Cowboys (43-20) on Friday can clinch a spot in next week's finals with a win. Arizona (45-22) plays UC Santa Barbara in an elimination game Wednesday.

Arizona looked to have a runner on base with one out in the ninth when first-base umpire John Haggerty ruled Dustin Williams' foot came off the bag as he stretched to catch third baseman Garrett Benge's throw on Zach Gibbons' grounder. The umpires conferred, and the safe call was overturned, sending Gibbons back to the dugout.

Cobb walked the next batter, but Ryan Aguilar grounded out to end the game.

Oklahoma State has played 19 straight shutout innings since super regionals and has allowed only six runs through seven NCAA Tournament games.

Buffett has allowed two runs in 22 innings in the national tournament. The junior from Albuquerque, a seventh-round draft pick of the Houston Astros, is a distant cousin of billionaire investor Warren Buffett, who lives in Omaha. The two met for the first time Sunday night.

Buffett got a big hand from his defense. Center fielder Ryan Sluder made the best catch of the CWS so far when he robbed Cody Ramer to start the game. After Jared Oliva walked with one out in the eighth, shortstop Walton went to his right to backhand Louis Boyd's grounder to start a 6-4-3 double play.

The game was delayed 2 hours, 21 minutes because of lightning in the area.

Texas, in 2014, was the last team at the CWS to post back-to-back shutouts.